Add module support and tests. (#174)

test/module/regex_token_iterator_eg_2.cpp

@@ -0,0 +1,99 @@
+/*
+ *
+ * Copyright (c) 2003-2022
+ * John Maddock
+ *
+ * Use, modification and distribution are subject to the 
+ * Boost Software License, Version 1.0. (See accompanying file 
+ * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+ *
+ */
+
+ /*
+  *   LOCATION:    see http://www.boost.org for most recent version.
+  *   FILE         regex_token_iterator_example_2.cpp
+  *   VERSION      see <boost/version.hpp>
+  *   DESCRIPTION: regex_token_iterator example: spit out linked URL's.
+  */
+
+#if (defined(__cpp_lib_modules) || (defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 193833135))) && !defined(TEST_HEADERS)
+import std;
+#elif defined(MSVC_EXPERIMENTAL_STD_MODULE) && !defined(TEST_HEADERS)
+import std.core;
+#else
+#include <fstream>
+#include <iostream>
+#include <iterator>
+#endif
+
+#ifdef TEST_HEADERS
+#include <boost/regex.hpp>
+#else
+import boost.regex;
+#endif
+
+boost::regex e("<\\s*A\\s+[^>]*href\\s*=\\s*\"([^\"]*)\"",
+               boost::regex::normal | boost::regex::icase);
+
+void load_file(std::string& s, std::istream& is)
+{
+   s.erase();
+   if(is.bad()) return;
+   //
+   // attempt to grow string buffer to match file size,
+   // this doesn't always work...
+   s.reserve(static_cast<std::string::size_type>(is.rdbuf()->in_avail()));
+   char c;
+   while(is.get(c))
+   {
+      // use logarithmic growth stategy, in case
+      // in_avail (above) returned zero:
+      if(s.capacity() == s.size())
+         s.reserve(s.capacity() * 3);
+      s.append(1, c);
+   }
+}
+
+int main(int argc, char** argv)
+{
+   std::string s;
+   int i;
+   for(i = 1; i < argc; ++i)
+   {
+      std::cout << "Findings URL's in " << argv[i] << ":" << std::endl;
+      s.erase();
+      std::ifstream is(argv[i]);
+      load_file(s, is);
+      is.close();
+      boost::sregex_token_iterator i(s.begin(), s.end(), e, 1);
+      boost::sregex_token_iterator j;
+      while(i != j)
+      {
+         std::cout << *i++ << std::endl;
+      }
+   }
+   //
+   // alternative method:
+   // test the array-literal constructor, and split out the whole
+   // match as well as $1....
+   //
+   for(i = 1; i < argc; ++i)
+   {
+      std::cout << "Findings URL's in " << argv[i] << ":" << std::endl;
+      s.erase();
+      std::ifstream is(argv[i]);
+      load_file(s, is);
+      is.close();
+      const int subs[] = {1, 0,};
+      boost::sregex_token_iterator i(s.begin(), s.end(), e, subs);
+      boost::sregex_token_iterator j;
+      while(i != j)
+      {
+         std::cout << *i++ << std::endl;
+      }
+   }
+
+   return 0;
+}
+
+